Major Depressive Disorder. Mood Disorders. Extremely disabling, second only to heart disease Associated with Suicide; 15% w/ MDD complete suicide MDD most serous and widely studied depressive disorder Individuals must have anhedonia or depressed mood for at least two weeks period of time.
Heritability and specific environmental factors such as stress affecting one twin but not the other appear to be important.
--Correlation between MZ twins is .46, compared with DZ twins is .20.
Genetic propensity exists but learning and environmental factors play an important role
Threats to economic security
Cummulative Negative Events
Traumatic Events (defined by Criterion A)